Recent years have seen resurgence in the popularity and use of herbal supplements as aid in healthy lifestyle. With the growing demand there have also been a lot of debates about efficacy, quality and safety of these products. While a significant compendium of information has been compiled to resolve questions related to these issues, it is clear that more work needs to be done. Unfortunately, there is no “universal” method that can authenticate every plant sample or botanical supplement. For each sample, there needs to be a full understanding of the constituents being considered and what method(s) are specifically applicable to that material. However use of common approaches and research techniques should direct the developments in the field of pharmacognosy and natural products chemistry. This book presents applicability of such research methodologies using two specific botanicals as examples, namely Hoodia gordonii and Caralluma fimbriata. These two succulent plants are used as weight-loss supplements. Studies presented in this book have generated fundamental information about these plants and should answer some of the questions about H. gordonii and C. fimbriata.